Sustainable Development of Subsurface Energy Technologies: Geologic CO2 Storage and High-volume Hydraulic Fracturing
As we continue to pursue fossil fuel energy resources in a carbon-constrained world, our society is faced with the essential challenge of balancing our energy needs while continuing to be stewards of the environment. Two emerging energy technologies that have a strong potential to address these challenges are geologic CO2 sequestration in deep saline aquifers and shale gas extraction via hydraulic fracturing. However, successful mitigation of CO2 emissions through geologic storage will require that the integrity of caprock formations is ensured and the impact of hydraulic fracturing activities on water quality is poorly understood. This presentation will introduce these processes and discuss some of the associated research challenges related to assessing their sustainable development. Results from experimental investigations of CO2 leakage through a fractured carbonate caprock and the impact of geochemical alterations on fracture permeability will be presented. In addition, results from ongoing work examining the influence of hydraulic fracturing fluid chemicals in mobilizing trace toxic elements from organic-rich shales will be discussed.